The past two decades have witnessed a growing interest in comparative intelligence, the study of complex processes in animals that bear similarities to comparable processes in humans. In one significant respect, however, the study of animal intelligence has proceeded along a quite separate path from the study of similar processes in humans. The case in point concerns individual differences. Historically, there has been a distinct lack of interest in individual differences in animal intelligence. In the study of human intelligence individual differences have always been a central focus as well as the source of numerous important findings concerning the psychometric structure and underlying biology of intelligence. This proposal seeks funding for a research program that has the long-term goal of assessing whether reliable individual differences exist across a series of complex learning/memory tasks in mice. As a result of our recent work on spatial learning we are encouraged that some sort of commonality inheres to spatial tasks, but the generality and limitations of this commonality are unknown. The proposed set of experiments will delineate the nature of this commonality. The development of an animal model of individual differences in intelligence would for the first time allow experimental work to proceed to identify the mechanisms that underlie these differences.